A technique of performing a fail-safe at the time of failure of a rotation speed sensor of a secondary pulley in a continuously variable transmission is disclosed in JP5-46465B. In this technique, at the time of the failure of the rotation speed sensor of the secondary pulley, by fixing a speed ratio to the maximum speed ratio, that is, the lowest speed ratio, and fixing line pressure to the maximum line pressure, belt slippage is prevented. In this technique, the continuously variable transmission is shifted by a single pressure regulation method of fixing hydraulic control pressure of the secondary pulley to the line pressure.